--- /dev/null
+/*
+ * Imagination Technologies PowerDown Controller Watchdog Timer.
+ *
+ * Copyright (c) 2014 Imagination Technologies Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ * Based on drivers/watchdog/sunxi_wdt.c Copyright (c) 2013 Carlo Caione
+ * 2012 Henrik Nordstrom
+ */
+
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/log2.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/watchdog.h>
+
+/* registers */
+#define PDC_WDT_SOFT_RESET 0x00
+#define PDC_WDT_CONFIG 0x04
+ #define PDC_WDT_CONFIG_ENABLE BIT(31)
+ #define PDC_WDT_CONFIG_DELAY_MASK 0x1f
+
+#define PDC_WDT_TICKLE1 0x08
+#define PDC_WDT_TICKLE1_MAGIC 0xabcd1234
+#define PDC_WDT_TICKLE2 0x0c
+#define PDC_WDT_TICKLE2_MAGIC 0x4321dcba
+
+#define PDC_WDT_TICKLE_STATUS_MASK 0x7
+#define PDC_WDT_TICKLE_STATUS_SHIFT 0
+#define PDC_WDT_TICKLE_STATUS_HRESET 0x0 /* Hard reset */
+#define PDC_WDT_TICKLE_STATUS_TIMEOUT 0x1 /* Timeout */
+#define PDC_WDT_TICKLE_STATUS_TICKLE 0x2 /* Tickled incorrectly */
+#define PDC_WDT_TICKLE_STATUS_SRESET 0x3 /* Soft reset */
+#define PDC_WDT_TICKLE_STATUS_USER 0x4 /* User reset */
+
+/* Timeout values are in seconds */
+#define PDC_WDT_MIN_TIMEOUT 1
+#define PDC_WDT_DEF_TIMEOUT 64
+
+static int heartbeat;
+module_param(heartbeat, int, 0);
+MODULE_PARM_DESC(heartbeat, "Watchdog heartbeats in seconds. "
+ "(default = " __MODULE_STRING(PDC_WDT_DEF_TIMEOUT) ")");
+
+static bool nowayout = WATCHDOG_NOWAYOUT;
+module_param(nowayout, bool, 0);
+MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started "
+ "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
+
+struct pdc_wdt_dev {
+ struct watchdog_device wdt_dev;
+ struct clk *wdt_clk;
+ struct clk *sys_clk;
+ void __iomem *base;
+};
+
+static int pdc_wdt_keepalive(struct watchdog_device *wdt_dev)
+{
+ struct pdc_wdt_dev *wdt = watchdog_get_drvdata(wdt_dev);
+
+ writel(PDC_WDT_TICKLE1_MAGIC, wdt->base + PDC_WDT_TICKLE1);
+ writel(PDC_WDT_TICKLE2_MAGIC, wdt->base + PDC_WDT_TICKLE2);
+
+ return 0;
+}
+
+static int pdc_wdt_stop(struct watchdog_device *wdt_dev)
+{
+ unsigned int val;
+ struct pdc_wdt_dev *wdt = watchdog_get_drvdata(wdt_dev);
+
+ val = readl(wdt->base + PDC_WDT_CONFIG);
+ val &= ~PDC_WDT_CONFIG_ENABLE;
+ writel(val, wdt->base + PDC_WDT_CONFIG);
+
+ /* Must tickle to finish the stop */
+ pdc_wdt_keepalive(wdt_dev);
+
+ return 0;
+}
+
+static int pdc_wdt_set_timeout(struct watchdog_device *wdt_dev,
+ unsigned int new_timeout)
+{
+ unsigned int val;
+ struct pdc_wdt_dev *wdt = watchdog_get_drvdata(wdt_dev);
+ unsigned long clk_rate = clk_get_rate(wdt->wdt_clk);
+
+ wdt->wdt_dev.timeout = new_timeout;
+
+ val = readl(wdt->base + PDC_WDT_CONFIG) & ~PDC_WDT_CONFIG_DELAY_MASK;
+ val |= order_base_2(new_timeout * clk_rate) - 1;
+ writel(val, wdt->base + PDC_WDT_CONFIG);
+
+ return 0;
+}
+
+/* Start the watchdog timer (delay should already be set) */
+static int pdc_wdt_start(struct watchdog_device *wdt_dev)
+{
+ unsigned int val;
+ struct pdc_wdt_dev *wdt = watchdog_get_drvdata(wdt_dev);
+
+ val = readl(wdt->base + PDC_WDT_CONFIG);
+ val |= PDC_WDT_CONFIG_ENABLE;
+ writel(val, wdt->base + PDC_WDT_CONFIG);
+
+ return 0;
+}
+
+static struct watchdog_info pdc_wdt_info = {
+ .identity = "IMG PDC Watchdog",
+ .options = WDIOF_SETTIMEOUT |
+ WDIOF_KEEPALIVEPING |
+ WDIOF_MAGICCLOSE,
+};
+
+static const struct watchdog_ops pdc_wdt_ops = {
+ .owner = THIS_MODULE,
+ .start = pdc_wdt_start,
+ .stop = pdc_wdt_stop,
+ .ping = pdc_wdt_keepalive,
+ .set_timeout = pdc_wdt_set_timeout,
+};
+
+static int pdc_wdt_probe(struct platform_device *pdev)
+{
+ int ret, val;
+ unsigned long clk_rate;
+ struct resource *res;
+ struct pdc_wdt_dev *pdc_wdt;
+
+ pdc_wdt = devm_kzalloc(&pdev->dev, sizeof(*pdc_wdt), GFP_KERNEL);
+ if (!pdc_wdt)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ pdc_wdt->base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(pdc_wdt->base))
+ return PTR_ERR(pdc_wdt->base);
+
+ pdc_wdt->sys_clk = devm_clk_get(&pdev->dev, "sys");
+ if (IS_ERR(pdc_wdt->sys_clk)) {
+ dev_err(&pdev->dev, "failed to get the sys clock\n");
+ return PTR_ERR(pdc_wdt->sys_clk);
+ }
+
+ pdc_wdt->wdt_clk = devm_clk_get(&pdev->dev, "wdt");
+ if (IS_ERR(pdc_wdt->wdt_clk)) {
+ dev_err(&pdev->dev, "failed to get the wdt clock\n");
+ return PTR_ERR(pdc_wdt->wdt_clk);
+ }
+
+ ret = clk_prepare_enable(pdc_wdt->sys_clk);
+ if (ret) {
+ dev_err(&pdev->dev, "could not prepare or enable sys clock\n");
+ return ret;
+ }
+
+ ret = clk_prepare_enable(pdc_wdt->wdt_clk);
+ if (ret) {
+ dev_err(&pdev->dev, "could not prepare or enable wdt clock\n");
+ goto disable_sys_clk;
+ }
+
+ /* We use the clock rate to calculate the max timeout */
+ clk_rate = clk_get_rate(pdc_wdt->wdt_clk);
+ if (clk_rate == 0) {
+ dev_err(&pdev->dev, "failed to get clock rate\n");
+ ret = -EINVAL;
+ goto disable_wdt_clk;
+ }
+
+ if (order_base_2(clk_rate) > PDC_WDT_CONFIG_DELAY_MASK + 1) {
+ dev_err(&pdev->dev, "invalid clock rate\n");
+ ret = -EINVAL;
+ goto disable_wdt_clk;
+ }
+
+ if (order_base_2(clk_rate) == 0)
+ pdc_wdt->wdt_dev.min_timeout = PDC_WDT_MIN_TIMEOUT + 1;
+ else
+ pdc_wdt->wdt_dev.min_timeout = PDC_WDT_MIN_TIMEOUT;
+
+ pdc_wdt->wdt_dev.info = &pdc_wdt_info;
+ pdc_wdt->wdt_dev.ops = &pdc_wdt_ops;
+ pdc_wdt->wdt_dev.max_timeout = 1 << PDC_WDT_CONFIG_DELAY_MASK;
+ pdc_wdt->wdt_dev.parent = &pdev->dev;
+
+ ret = watchdog_init_timeout(&pdc_wdt->wdt_dev, heartbeat, &pdev->dev);
+ if (ret < 0) {
+ pdc_wdt->wdt_dev.timeout = pdc_wdt->wdt_dev.max_timeout;
+ dev_warn(&pdev->dev,
+ "Initial timeout out of range! setting max timeout\n");
+ }
+
+ pdc_wdt_stop(&pdc_wdt->wdt_dev);
+
+ /* Find what caused the last reset */
+ val = readl(pdc_wdt->base + PDC_WDT_TICKLE1);
+ val = (val & PDC_WDT_TICKLE_STATUS_MASK) >> PDC_WDT_TICKLE_STATUS_SHIFT;
+ switch (val) {
+ case PDC_WDT_TICKLE_STATUS_TICKLE:
+ case PDC_WDT_TICKLE_STATUS_TIMEOUT:
+ pdc_wdt->wdt_dev.bootstatus |= WDIOF_CARDRESET;
+ dev_info(&pdev->dev,
+ "watchdog module last reset due to timeout\n");
+ break;
+ case PDC_WDT_TICKLE_STATUS_HRESET:
+ dev_info(&pdev->dev,
+ "watchdog module last reset due to hard reset\n");
+ break;
+ case PDC_WDT_TICKLE_STATUS_SRESET:
+ dev_info(&pdev->dev,
+ "watchdog module last reset due to soft reset\n");
+ break;
+ case PDC_WDT_TICKLE_STATUS_USER:
+ dev_info(&pdev->dev,
+ "watchdog module last reset due to user reset\n");
+ break;
+ default:
+ dev_info(&pdev->dev,
+ "contains an illegal status code (%08x)\n", val);
+ break;
+ }
+
+ watchdog_set_nowayout(&pdc_wdt->wdt_dev, nowayout);
+
+ platform_set_drvdata(pdev, pdc_wdt);
+ watchdog_set_drvdata(&pdc_wdt->wdt_dev, pdc_wdt);
+
+ ret = watchdog_register_device(&pdc_wdt->wdt_dev);
+ if (ret)
+ goto disable_wdt_clk;
+
+ return 0;
+
+disable_wdt_clk:
+ clk_disable_unprepare(pdc_wdt->wdt_clk);
+disable_sys_clk:
+ clk_disable_unprepare(pdc_wdt->sys_clk);
+ return ret;
+}
+
+static void pdc_wdt_shutdown(struct platform_device *pdev)
+{
+ struct pdc_wdt_dev *pdc_wdt = platform_get_drvdata(pdev);
+
+ pdc_wdt_stop(&pdc_wdt->wdt_dev);
+}
+
+static int pdc_wdt_remove(struct platform_device *pdev)
+{
+ struct pdc_wdt_dev *pdc_wdt = platform_get_drvdata(pdev);
+
+ pdc_wdt_stop(&pdc_wdt->wdt_dev);
+ watchdog_unregister_device(&pdc_wdt->wdt_dev);
+ clk_disable_unprepare(pdc_wdt->wdt_clk);
+ clk_disable_unprepare(pdc_wdt->sys_clk);
+
+ return 0;
+}
+
+static const struct of_device_id pdc_wdt_match[] = {
+ { .compatible = "img,pdc-wdt" },
+ {}
+};
+MODULE_DEVICE_TABLE(of, pdc_wdt_match);
+
+static struct platform_driver pdc_wdt_driver = {
+ .driver = {
+ .name = "imgpdc-wdt",
+ .of_match_table = pdc_wdt_match,
+ },
+ .probe = pdc_wdt_probe,
+ .remove = pdc_wdt_remove,
+ .shutdown = pdc_wdt_shutdown,
+};
+module_platform_driver(pdc_wdt_driver);
+
+MODULE_AUTHOR("Jude Abraham <Jude.Abraham@imgtec.com>");
+MODULE_AUTHOR("Naidu Tellapati <Naidu.Tellapati@imgtec.com>");
+MODULE_DESCRIPTION("Imagination Technologies PDC Watchdog Timer Driver");
+MODULE_LICENSE("GPL v2");
git.openpandora.org / pandora-kernel.git / commitdiff